Epidemiology of polycythemia vera in a Mexican population

Epidemiology of polycythemia vera (PV) is derived from cohort studies in Western populations. PV studies in the Latin population are limited and have described a lower prevalence of JAK2 mutation. A retrospective cohort of 90 Mexican patients from a single center with PV according to the 2016 World Health Organization diagnostic criteria was studied to establish clinical presentation in Mexicans and evaluate risk factors for mortality and vascular events. At diagnosis, the median age was 59 years; half were females, 90.7% harbored the JAK2 V617F mutation, and 7.1% had an exon 12 mutation. Arterial and venous thromboses were observed in 13.3 and 27.8% of patients, respectively. Seventy-one patients received hydroxyurea and one interferon alpha-2a, of which 51.5% achieved a complete response and 25.0% a partial response. The incidence rate for postdiagnosis arterial thrombosis was 2.68 cases per 100 person–years, for venous thrombosis 2.84, for major hemorrhage 2.57, for progression to myelofibrosis 1.14, and for leukemic transformation 0.44. The mortality rate was 3.54 cases per 100 person–years, and median of survival was 150 months. In multivariable analysis, survival was adversely affected by leukocytosis ≥12 × 10⁹/L (p = 0.013); thrombocytosis ≥450 × 10⁹/L was a risk factor for arterial thrombosis (p = 0.023), and anticoagulation at diagnosis for major hemorrhage (p = 0.049). In conclusion, epidemiology of PV in Mexican population is similar to that reported in Western studies, but with more venous thrombosis at diagnosis and a higher incidence of vascular complications postdiagnosis.